Energy and Work January 2015 Arsenie groups of

Energy and Work January 2015 Arsenie

_____groups of Energy n ______Energy (PE) n It _____shown through ______ n Energy is stored and ready to do work n Elastic PE – a spring, a rubberband, a bow n Chemical PE – batteries, gasoline n Nuclear PE – the sun, bombs n _______PE – any object elevated n ______Energy (KE) n Object is in motion n ENERGY of MOTION

What is “_____” Energy? Mechanical energy refers to objects in motion or that have the potential to move. n It is the… n n Mechanical Energy is the property of an object that enables it to do ‘_____’.

Work is the _____of a ______ Work is the product of the _______(F) on an object and the ____(d) that object moved (in the same direction as the force). Work is done to either: n change… n against….

SI Metric Units of Energy is measured in ____(J). This includes Work, Potential Energy, or Kinetic Energy. 1 Joule = 1 ______x 1 _______ 1 Newton x 1 meter is also called a “____-____”.

Example problem think! You lift a 100 -N boulder 2 m. Q. How much work is done on the boulder? Answer:

_______Energy: Gravity exerts a force on this boulder. In order to move it, work must be done (against the existing force of gravity). Which example requires more work? • The boulder is lifted with 100 N of force. • The boulder is pushed up the 4 -m incline with 50 N of force. • The boulder is lifted with 100 N of force up each 0. 5 -m stair. Trick question! Answer:

Potential Energy n But, it’s also ______and ______to Work!!!!!! n Because we would have to do work against gravity to lift something to get it elevated to store PE Therefore, PE _______to Work! So, what is the gravitational potential energy of the boulder in the lifted position? Answer: n Why?

and So, Then, Therefore, W is equal and opposite to PE

Kinetic Energy But it’s ALSO _______to the work required to bring something to its final motion or to rest because it is a conversion of potential energy. …and potential energy is also equal to work and measured in Joules, and work is equal to force multiplied by distance. Therefore: n

The Law of _____of ______ n n We have discovered a natural law of the universe that all energy is conserved. Energy is not ______or _______. All the energy that was here in the beginning is still here, and will be here until the end. Energy simply converts from one form to another. For example, PE converts to KE.

Forms of Energy __________ n Radiant (electromagnetic) n ______ n Magnetic n ______ n Sound n ______ n Luminous n Mass (E=mc 2) n Dark (theoretical) n _______ n Can you categorize each of these as Potential or Kinetic?

Forms of Energy Thermal (KE) n Elastic (KE) n Chemical (PE) n Sound (KE) n Electric (KE) n Mechanical (PE) n Radiant (KE) n Luminous (KE) (electromagnetic) n Mass (E=mc 2) n Nuclear (PE) (KE) n Magnetic (KE) n Gravitational (KE) n Nutritional/food (PE) n Dark (theoretical) n